The problem of debris collecting within gutters is well documented. Many different forms of gutter guard systems have been developed to prevent debris from collecting within the gutter. Some such gutter guards are of a type that provides merely a solid plane with holes therein so that water can pass through but debris cannot. Such simple systems suffer from the serious drawback that the holes must be large enough that water will pass through rather than adhering due to surface tension and adhesion forces to edges of the holes as noted by Higginbotham in U.S. Pat. No. 6,598,352. On the other hand, the holes must be small enough to prevent debris from passing through. Experience has shown that the compromises required with such simple gutter guard systems lead to serious deficiencies in the performance of such gutter guard systems, either not effectively allowing water to pass through or too often allowing debris to pass through or lodge within the holes.
Other gutter guard systems utilize solid planes of material with a sharp curve in the surface which water can adhere to, but which debris will not adhere to. Water adheres to the sharply curving metal portion and is routed in a curving path into the gutter, while debris falls off of such a gutter guard. Such gutter guards have advantages and disadvantages which are well documented in the prior art: chiefly, as taught by Higginbotham in U.S. Pat. No. 6,598,352: oil from shingles eventually coats and waterproofs such systems requiring that the be manually and periodically cleaned.
A third form of gutter guard known in the prior art and first introduced in U.S. Pat. No. 6,598,352 by Higginbotham utilizes a fine mesh filter element which has sufficiently small holes therein that debris cannot pass through and this fine mesh filter element, which is formed as a thin flexible screen material, is supported upon a rigid underlying support structure that holds the filter element in place, with the underlying support structure having holes therein to route water passing through the filter element down through the support structure and into the gutter. Such two part filter and support structure gutter guards allow substantially all debris to be prevented from the gutter while allowing high volumes of water to be directed into the gutter.
A common problem experienced by all different types of gutter guard systems in certain environments is that when freezing temperatures are encountered, water on and adjacent to the gutter guard will freeze, and prevent water from passing into the gutter. When such gutter guard performance is inhibited, freeze and thaw cycles can result in dangerously large icicles forming off of edges of the gutters or other portions of the roof. Freeze-thaw cycles that occur may result in ice dam formation. Additionally, the weight of the snow and ice on the gutter guard can potentially damage the gutter or gutter guard.
One solution for de-icing gutters and gutter guards is the use of heat cables. In at least one case, a gutter guard of the curving metal cover type has had such a heat cable affixed into the gutter guard so that the surface of the gutter guard could conduct heat from the resistance heating wire to melt frozen water off of the gutter. Such a system is described in U.S. Pat. No. 7,448,167 to Bachman, incorporated by reference herein in its entirety.
As noted by Lenney in his U.S. Patent application 20100287846 incorporated by reference herein in its entirety: “Because such curving metal style gutter guards have a single layer of metal forming the entire gutter guard, the wires can simply heat surfaces which come in contact with the frozen water. However, such a solution is not applicable to multi-part gutter guard systems, such as those described below which include a filter element and an underlying support structure. In particular, filter elements are beneficially formed from materials which resist corrosion. Such materials are also generally low in thermal conductance. For instance, of all metals, stainless steel is known for its low corrosion characteristics, but is also known for being very low in thermal conductance, especially for a steel alloy. Such low thermal conductance of screen materials can require either excessive electric power to be routed to the gutter guard system to cause ice thereon to be melted, or suffers from lack of sufficient heat transfer, so that only limited melting of frozen water occurs.”
A drawback of the type of heating system offered by Lenney and described in his application is that much of his water receiving area is lost due to his utilization of a solid cover over the heating element. Another drawback of the method disclosed by Lenney is the high cost of manufacture and of installation of the product his application is associated with, “Ice Blaster™”, known to be as much as $40.00 (forty dollars) per linear foot in the field. Yet another drawback of the Lenney system is that the solid cover he discloses lessens the intensity of heat that could be delivered to the underside of ice overlying the cover versus heat radiating from a heating cable through a screen or mesh. Yet another drawback of the Lenney system is that the heating cable's placement and heat disbursement is limited to the narrowly defined covered channel he teaches. Yet another drawback of the Lenney system is that, in areas where icing is not a problem, the system offers only greater cost with less water receiving and redirecting performance. Yet another drawback of the Lenney system is that the heating cable is not easily installed or, if need be for repair, removed in that it requires affixing the solid channel cover and entire gutter guard system, by screws, to the front top lip of a rain gutter.
Accordingly, the present invention addresses a need that exists for a gutter guard system that is easily and readily installed, that may be installed as a retrofit to existing gutter guards, that is inexpensive, that does not interfere with micro-mesh products' ability to receive and redirect water, and that allows for the placement of a heating cable in more than one location.